Oral formulations of kappa opioid receptor agonists

ABSTRACT

The invention provides formulations for oral delivery of a therapeutic agent wherein the formulation comprises a kappa opioid receptor agonist and an absorption enhancer, the absorption enhancer includes a medium chain fatty acid or a salt of a medium chain fatty acid; and a medium chain fatty acid glyceride. The kappa opioid receptor agonist may be embedded in an oligosaccharide, such as trehalose. Also provided are capsules containing the oral formulations of the kappa opioid receptor agonists and the absorption enhancer of the invention and methods use of these formulations for the prophylaxis and treatment of variety of kappa opioid receptor-associated diseases and conditions such as pain, pruritus and inflammation; the method comprising administering to the mammal the formulation comprising the kappa opioid receptor agonist and an absorption enhancer.

FIELD OF THE INVENTION

The invention relates to a formulation for oral delivery of atherapeutic agent. The formulation includes a therapeutic agent in theform of an active pharmaceutical ingredient (API), a medium chain fattyacid or a salt of a medium chain fatty acid, and a medium chain fattyacid glyceride. Suitable active pharmaceutical ingredients include kappaopioid receptor agonists such as D-amino acid peptide amides.

The invention further relates to methods of prophylaxis or treatment ofkappa opioid receptor-associated diseases and conditions in a humanpatient or other mammal, the method comprising administering to thepatient or the mammal the oral formulation of the invention.

BACKGROUND

Kappa opioid receptor agonists are a new class of therapeutic agentsthat have unique physicochemical properties leading to the need for newformulations for efficient delivery and sufficient bioavailability forefficacy of prophylaxis or treatment of kappa opioid receptor-associateddiseases and conditions. New Kappa include the synthetic peptide amidesdisclosed in U.S. Pat. Nos. 7,402,564, 7,713,937 and 7,842,662 toSchteingart et al. and asimadoline(N-[(1S)-2-[(3S)-3-hydroxypyrrolidin-1-yl]-1-phenylethyl]-N-methyl-2,2-diphenylacetamide),as well as nalfurafine((2E)-N-[(5α,6β)-17-(cyclopropylmethyl)-3,14-dihydroxy-4,5-epoxymorphinan-6-yl]-3-(3-furyl)-N-methylacrylamide).

Pharmaceutical formulations can be tailored for different deliveryroutes, such as for intra venous or intra muscular injection, fortopical application, or for oral administration. Each of theseformulations must meet the particular stability requirements that permitstorage for a period of time after manufacture and before administrationto the patient. In certain circumstances the different components of theformulation may interact over time resulting in a reduction in long termstability. Suitable formulations and additives for maximizingbioavailability of particular kappa opioid receptor agonists areunpredictable.

SUMMARY OF THE INVENTION

The present invention provides a formulation for oral delivery of atherapeutic agent that includes a kappa opioid receptor agonist and anabsorption enhancer. In one embodiment, the formulation of the inventionincludes a medium chain fatty acid or a salt of a medium chain fattyacid, and a medium chain fatty acid glyceride as absorption enhancerssuitable for optimizing uptake of the kappa opioid receptor agonist fromthe gastrointestinal system and thereby enhancing its biologicalactivity. In one alternative, the invention provides an oral formulationincluding a medium chain fatty acid or a salt of a medium chain fattyacid, and no medium chain fatty acid glyceride. In another alternative,the invention provides an oral formulation including a medium chainfatty acid glyceride and no medium chain fatty acid or a salt of amedium chain fatty acid.

The invention further provides a bioactive composition that includes abiologically active peptide embedded in an oligomeric saccharide forminga particle including the stabilized biologically active peptide. Thebiologically active peptide can be any suitable biologically activepeptide, such as for instance a biologically active peptide thatincludes one or more D-amino acids. In one embodiment, the biologicallyactive peptide that includes one or more D-amino acids is a kappa opioidreceptor agonist. The biologically active peptide kappa opioid receptoragonist that includes one or more D-amino acids can be any suitablebiologically active peptide kappa opioid receptor agonist that includesone or more D-amino acids such as for instance, and without limitation,any of the peptide kappa opioid receptor agonists disclosed in U.S. Pat.No. 7,402,564. In one embodiment, the biologically active peptide kappaopioid receptor agonist that includes one or more D-amino acids is(D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopyperidine-4carboxylic acid)]-OH alsoknown as CR845, as disclosed and identified as compound 2 in U.S. Pat.No. 7,402,564.

In another embodiment of the invention, the formulation for oraldelivery of a therapeutic agent, interchangeably referred to herein asthe oral formulation of the invention, includes a peptide amide kappaopioid receptor agonist which contains one or more D-amino acids and amedium chain fatty acid or a salt of a medium chain fatty acid, and amedium chain fatty acid glyceride as absorption enhancers. The peptideamide kappa opioid receptor agonist which contains one or more D-aminoacids can be any suitable peptide amide containing at least one D-aminoacid, such as for instance, but not limited to, any of the syntheticpeptide amides disclosed in U.S. Pat. Nos. 7,402,564, 7,713,937 and7,842,662 to Schteingart et al., the entire disclosures of which areherein incorporated by reference.

In another embodiment, the bioactive composition includes a biologicallyactive peptide embedded in an oligomeric saccharide forming a particleincluding the stabilized biologically active peptide, wherein theoligomeric saccharide includes a disaccharide. The disaccharide can beany suitable disaccharide, such as for instance, a disaccharide thatincludes one or more glucose monomers. In one embodiment, thedisaccharide includes trehalose, the 1,1-α-glycoside linked glucosedimer. In a particular embodiment the disaccharide can consist entirelyof trehalose.

In one embodiment, the bioactive composition includes a biologicallyactive peptide embedded in an oligomeric saccharide to form a particleincluding the stabilized biologically active peptide, wherein theoligomeric saccharide enhances the stability of the biologically activepeptide over at least a year at 25° C.

In another embodiment of the oral formulation of the invention, the oralformulation includes a peptide amide kappa opioid receptor agonist andone or more absorption enhancers, wherein the peptide amide kappa opioidreceptor agonist has a structure of the following formula:Xaa₁-Xaa₂-Xaa₃-Xaa₄-(G)  Formula I

In another embodiment of the oral formulation of the invention, the oralformulation includes a peptide amide kappa opioid receptor agonist andone or more absorption enhancers, wherein the peptide amide kappa opioidreceptor agonist is CR845 having the structure of the following formula:

D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopiperidine-4-carboxylic acid)]-OH.

In still another embodiment, the oral formulation of the inventionincludes a peptide amide kappa opioid receptor agonist that includes oneor more D-amino acids, and an absorption enhancer; wherein the syntheticpeptide amide including one or more D-amino acids is CR845 and theabsorption enhancer includes a medium chain fatty acid or apharmaceutically acceptable salt of a medium chain fatty acid, and amedium chain fatty acid glyceride.

The present invention further provides methods of use of a formulationfor oral delivery of a therapeutic agent that includes a kappa opioidreceptor agonist and an absorption enhancer for the prophylaxis ortreatment of kappa opioid receptor-associated diseases and conditions ina human patient or other mammal, the method comprising administering tothe patient or the mammal the oral formulation of the invention. In oneembodiment, the formulation of the invention includes a medium chainfatty acid or a salt of a medium chain fatty acid, and a medium chainfatty acid glyceride as absorption enhancers suitable for optimizinguptake of the kappa opioid receptor agonist from the gastrointestinalsystem and thereby enhancing its biological activity.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 : Bioavailability of CR845 post oral administration to canines(n=8) of a formulation containing (1) 1.6 mg spray dried CR845.HCl in90% Miglyol® 812, 10% sodium caprate; (2) 1.6 mg crystallized CR845.HClin 90% Miglyol® 812, 10% sodium caprate; (3) 1.6 mg spray driedCR845.HCl in 90% Miglyol® 812, 10% capric acid; (4) 1.6 mg spray driedCR845.HCl in 70% Miglyol® 812, 30% capric acid.

FIG. 2 : Dissolution profile of formulation 1 containing 1.6 mg spraydried CR845.HCl in 90% Miglyol® 812, 10% sodium caprate on a scale of0-300 mins.

FIG. 3 : Dissolution profile of formulation 2 containing 1.6 mg spraydried CR845.HCl in 90% Miglyol® 812, 10% capric acid on a scale of 0-300mins.

FIG. 4 : Dissolution profile of formulation 3 containing 1.6 mg spraydried CR845.HCl in 70% Miglyol® 812, 30% capric acid on a scale of 0-300mins.

FIG. 5 : Dissolution profile of formulation 4 containing 1.6 mgcrystallized CR845.HCl in 90% Miglyol® 812, 10% sodium caprate on ascale of 0-300 mins.

FIG. 6 : Plasma concentration profile of formulation 5 containing 4.0 mgCR845.HCl, 20% capric acid in Miglyol® 812.

FIG. 7 : Plasma concentration profile of formulation 6 containing 4.0 mgCR845.HCl, 10% capric acid in Miglyol® 812.

FIG. 8 : Plasma concentration profile of formulation 7 containing 4.0 mgCR854, 5% capric acid in Miglyol® 812.

FIG. 9 : Suspensions of CR845.HCl with 0% or 10% sodium caprate; or 0%or 10% sodium caprate plus EDTA after standing and 30 inversions after Imonth storage at 40° C. Photomicrographs show consistent particle sizeafter 1 month or 2 months storage at 40° C.

FIG. 10 : Plasma concentration profile of formulation 8 containing 2.0mg spray dried CR845.HCl (21% w/w), trehalose (70% w/w), 9% (w/w) EDTA,suspended in 10% capric acid in Miglyol® 812.

FIG. 11 : Plasma concentration profile of formulation 9 containing 2.0mg spray dried CR845.HCl (19% w/w), trehalose (62% w/w), sodium caprate(14% w/w), EDTA (5% w/w), in Miglyol® 812.

FIG. 12 : Plasma concentration profile of formulation 10 containing 2.0mg spray dried CR845.HCl (18% w/w), trehalose (60% w/w), sodium caprate(13% w/w), EDTA (9% w/w), in Miglyol® 812.

FIG. 13 : Plasma concentration profile of formulation 11 containing 2.0mg spray dried CR845.HCl (18% w/w), trehalose (60% w/w), sodium caprate(22% w/w), in Miglyol® 812.

FIG. 14 : Plasma concentration profile of formulation 12 containing 2.0mg spray dried CR845.HCl (23% w/w), trehalose (77% w/w), suspended in10% capric acid, Miglyol® 812.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the oral formulation of the invention includes atherapeutic agent comprising a peptide, and at least one absorptionenhancer, the absorption enhancer includes a medium chain fatty acid ora salt of a medium chain fatty acid, and a medium chain fatty acidglyceride, wherein the medium chain fatty acid or the salt of the mediumchain fatty acid comprises capric acid or a salt of capric acid.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist peptide, and at least one absorptionenhancer, the absorption enhancer includes a medium chain fatty acid ora salt of a medium chain fatty acid, and a medium chain fatty acidglyceride, wherein the medium chain fatty acid or the salt of the mediumchain fatty acid comprises capric acid or a salt of capric acid.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and at least one absorption enhancer, the absorption enhancer includes amedium chain fatty acid or a salt of a medium chain fatty acid, and amedium chain fatty acid glyceride, wherein the medium chain fatty acidor the salt of the medium chain fatty acid comprises capric acid or asalt of capric acid. The salt of capric acid can be any suitable salt ofcapric acid, such as for instance, sodium caprate.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and at least one absorption enhancer, the absorption enhancer includes amedium chain fatty acid or a salt of a medium chain fatty acid, and amedium chain fatty acid glyceride, wherein the medium chain fatty acidglyceride comprises a medium chain fatty acid triglyceride. The mediumchain triglyceride can be any suitable medium chain fatty acidtriglyceride, such as for instance, and without limitation, one or moreof Miglyol® 810, Miglyol® 812 (caprylic/capric fatty aciddi-/tri-glyceride), Capmul® CM (glyceryl mono/di-caprylate/caprate),Neobee® 1053 or the caprylic/capric triglyceride: Neobee® M5.

In one alternative, a suitable additional absorption enhancers can beincluded, such as lipophilic surfactants, for instance, a propyleneglycol mono-di-caprylate/caprate e.g. Capmul® PGMC; a propylene glycoldi-caprate such as Captex® 100, or a propylene glycoldi-caprylate/caprate such as Captex® 200 to supplement the medium chainfatty acid triglyceride(s) in the kappa opioid receptor agonistformulations of the invention.

In another alternative, the suitable additional absorption enhancersthat can be included can a hydrophilic surfactant such as for instanceTween® 80 (Polyoxyethylene 20 sorbitan mono-oleate), Tween® 60(Polyoxyethylene 20 sorbitan mono-stearate), Lubrasol® ALF(PEG-8-caprylic/capric glycerides), Kolliphor® EL (PEG-35 glycerylricinoleate), Kolliphor® HS 15 (PEH-15 hydroxystearate), and Gelucare®44/14 (Lauroyl PEG-32 mono/di/tri-glycerides) can be added to supplementthe medium chain fatty acid triglyceride(s) in the kappa opioid receptoragonist formulations.

In one embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and an absorption enhancer, wherein the absorption enhancer includesfrom about 0.01% to about 5% (w/w) of a kappa opioid receptor agonistsuch as CR845; from about 25% to about 92% (w/w) Miglyol® 812; and fromabout 5% to about 50% (w/w) capric acid.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and an absorption enhancer, wherein the absorption enhancer includesfrom about 0.1% to about 1% (w/w) of a kappa opioid receptor agonistsuch as CR845; from about 60% to about 90% (w/w) Miglyol® 812; and fromabout 10% to about 40% (w/w) capric acid.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and an absorption enhancer, wherein the absorption enhancer includes0.5% (w/w) of a kappa opioid receptor agonist such as CR845; about 70%(w/w) Miglyol® 812; and 30% (w/w) capric acid.

In still another embodiment, the oral formulation of the inventionincludes a kappa opioid receptor agonist that includes one or moreD-amino acids, and an absorption enhancer, wherein the absorptionenhancer includes 0.5% (w/w) of a kappa opioid receptor agonist such asCR845; about 90% (w/w) Miglyol® 812; and 10% (w/w) capric acid.

In another embodiment, the oral formulation of the invention includes akappa opioid receptor agonist that includes one or more D-amino acids,and an absorption enhancer, wherein the absorption enhancer includesfrom about 0.1% to about 1% (w/w) of a kappa opioid receptor agonistsuch as CR845; from about 60% to about 95% (w/w) Miglyol® 812; and fromabout 1% to about 20% (w/w) sodium caprate.

In still another embodiment, the oral formulation of the inventionincludes a kappa opioid receptor agonist that includes one or moreD-amino acids, and an absorption enhancer, wherein the absorptionenhancer includes about 0.5% (w/w) of a kappa opioid receptor agonistsuch as CR845; about 90% (w/w) Miglyol® 812; and about 10% (w/w) sodiumcaprate.

In one embodiment the kappa opioid receptor agonist can be optionallyembedded in a particle matrix of an oligomeric saccharide such as forinstance, trehalose.

The formulation of the invention including a kappa opioid receptoragonist that includes one or more D-amino acids, and at least oneabsorption enhancer, the absorption enhancer including a medium chainfatty acid or a salt of a medium chain fatty acid, and a medium chainfatty acid glyceride can be in the form of a gel or a capsule, whereinthe formulation further includes one or one of a pharmaceuticallyacceptable diluent, an excipient or a carrier. In one embodiment thecapsule is an enteric coated capsule or a capsule having intrinsicenteric properties.

In one embodiment, the formulation of the invention includes a kappaopioid receptor agonist such as but not limited to asimadoline(N-[(1S)-2-[(3S)-3-hydroxy-pyrrolidin-1-yl]-1-phenylethyl]-N-methyl-2,2-diphenylacetamide),or nalfurafine((2E)-N-[(5α,6β)-17-(cyclopropylmethyl)-3,14-dihydroxy-4,5-epoxymorphinan-6-yl]-3-(3-furyl)-N-methylacrylamide),and at least one absorption enhancer, the absorption enhancer includinga medium chain fatty acid or a salt of a medium chain fatty acid, and amedium chain fatty acid glyceride.

In another embodiment, the oral formulation of the invention includes atherapeutic agent comprising a peptide, and at least one absorptionenhancer, the absorption enhancer includes a medium chain fatty acid ora salt of a medium chain fatty acid, and a medium chain fatty acidglyceride, wherein the medium chain fatty acid or the salt of the mediumchain fatty acid comprises capric acid or a salt of capric acid, whereinthe formulation does not include a stabilizer, such aspolyvinylpyrolidine (PVP). Surprisingly, the formulations of theinvention have been found to be effective without the use of PVP orother such stabilizers.

Also provided is a method of treating or preventing a kappa opioidreceptor-associated disease or condition in a mammal. The methodincludes administering to the mammal a composition that includes aneffective amount of the above-described formulation of the invention.

The term “medium chain fatty acids” as used in this specification refersto one or more straight chain fatty acids including caproic acid (a C₆fatty acid), caprylic acid (a C₈ fatty acid), and capric acid (a C₁₀fatty acid).

The term “medium chain triglyceride” as used herein refers to aglyceride ester of one or more medium chain fatty acids as definedabove. The medium chain triglyceride can be any medium chaintriglyceride, such as a triglyceride of caproic acid (C₆ fatty acid), atriglyceride of caprylic acid (C₈ fatty acid), or a triglyceride ofcapric acid (C₁₀ fatty acid). Alternatively, the medium chaintriglyceride can be a triglyceride of a mixture of caproic acid andcaprylic acid; a mixture of caproic acid and capric acid; or a mixtureof caprylic acid and capric acid. In another alternative, the mediumchain triglyceride can be a triglyceride of a mixture of all three ofthe medium chain fatty acids: i.e. caproic acid, caprylic acid andcapric acid.

In one embodiment of the invention, the kappa opioid receptor agonistmay be suspended in Miglyol® or about 90% Miglyol® and about 10% sodiumcaprate. Alternatively, the kappa opioid receptor agonist may besuspended in about 95% Miglyol® and about 5% capric acid. Optionally,these formulations may include from about 5 to about 10% EDTA.

The nomenclature used to define the peptides and D-amino acid peptidesof the formulations of the invention is specified by Schroder & Lubke,The Peptides, Academic Press, 1965, wherein, in accordance withconventional representation, the N-terminus appears to the left and theC-terminus to the right. Where an amino acid residue has isomeric forms,both the L-isomer form and the D-isomer form of the amino acid areintended to be covered unless otherwise indicated. Amino acids arecommonly identified herein by the standard three-letter code. TheD-isomer of an amino acid is specified by the prefix “D-” as in “D-Phe”which represents D-phenylalanine, the D-isomer of phenylalanine.Similarly, the L-isomer is specified by the prefix “L-” as in “L-Phe.”Peptides are represented herein according to the usual convention asamino acid sequences from left to right: N-terminus to C-terminus,unless otherwise specified.

As used herein, D-Arg represents D-arginine, D-Har representsD-homoarginine, which has a side chain one methylene group longer thanD-Arg, and D-Nar represents D-norarginine, which has a side chain onemethylene group shorter than D-Arg. Similarly, D-Leu means D-leucine,D-Nle means D-norleucine, and D-Hle represents D-homoleucine. D-Alameans D-alanine, D-Tyr means D-tyrosine, D-Trp means D-tryptophan, andD-Tic means D-1,2,3,4-tetrahydroisoquinoline-3carboxylic acid. D-Valmeans D-valine and D-Met means D-methionine. D-Pro means D-proline,Pro-amide means the D- or L-form of proline amide. D-Pro amiderepresents D-proline with an amide formed at its carboxy moiety whereinthe amide nitrogen may be alkyl substituted, as in —NR_(a)R_(b), whereinR_(a) and R_(b) are each independently a C₁-C₆ alkyl group, or one ofR_(a) and R_(b) is —H. Gly means glycine, D-Ile means D-isoleucine,D-Ser means D-serine, and D-Thr means D-threonine. (E)D-Ala means theD-isomer of alanine which is substituted by the substituent (E) on theβ-carbon. Examples of such substituent (E) groups include tert-butyl,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, furyl, pyridyl,thienyl, thiazolyl and benzothienyl. Thus, cyclopentyl-D-Ala means theD-isomer of alanine which is substituted by cyclopentyl on the β-carbon.Similarly, D-Ala(2-thienyl) and (2-thienyl)D-Ala are interchangeable andboth mean the D-isomer of alanine substituted at the β-carbon withthienyl that is attached at the 2-ring position.

As used herein, D-Nal means the D-isomer of alanine substituted bynaphthyl on the β-carbon. D-2Nal means naphthyl substituted D-alaninewherein the attachment to naphthalene is at the 2-position on the ringstructure and D-1Nal means naphthyl-substituted D-alanine wherein theattachment to naphthalene is at the 1-position on the ring structure. By(A)(A′)D-Phe is meant D-phenylalanine substituted on the phenyl ringwith one or two substituents independently chosen from halo, nitro,methyl, halomethyl (such as, for example, trifluoromethyl),perhalomethyl, cyano and carboxamide. By D-(4-F)Phe is meantD-phenylalanine which is fluoro-substituted in the 4-position of thephenyl ring. By D-(2-F)Phe is meant D-phenylalanine which isfluoro-substituted in the 2-position of the phenyl ring. By D-(4-Cl)Pheis meant D-phenylalanine which is chloro substituted in the 4-phenylring position. By (α-Me)D-Phe is meant D-phenylalanine which is methylsubstituted at the alpha carbon. By (α-Me)D-Leu is meant D-leucine whichis methyl substituted at the alpha carbon.

The designations (B)₂D-Arg, (B)₂D-Nar, and (B)₂D-Har representD-arginine, D-norarginine and D-homoarginine, respectively, each havingtwo substituent (B) groups on the side chain. D-Lys means D-lysine andD-Hlys means D-homolysine. ζ-(B)D-Hlys, ε-(B)D-Lys, and ε-(B)₂-D-Lysrepresent D-homolysine and D-lysine each having the side chain aminogroup substituted with one or two substituent (B) groups, as indicated.D-Orn means D-ornithine and δ-(B)α-(B′)D-Orn means D-ornithinesubstituted with (B′) at the alpha carbon and substituted with (B) atthe side chain δ-amino group.

D-Dap means D-2,3-diaminopropionic acid. D-Dbu represents the D-isomerof alpha, gamma-diamino butyric acid and (B)₂D-Dbu represents alpha,gamma-diamino butyric acid which is substituted with two substituent (B)groups at the gamma amino group. Unless otherwise stated, each of the(B) groups of such doubly substituted residues are independently chosenfrom H— and C₁-C₄-alkyl. As used herein, D-Amf means D-(NH₂CH₂-)Phe,i.e., the D-isomer of phenylalanine substituted with aminomethyl on itsphenyl ring and D-4Amf represents the particular D-Amf in which theaminomethyl is attached at the 4-position of the ring. D-Gmf meansD-Amf(amidino) which represents D-Phe wherein the phenyl ring issubstituted with —CH₂NHC(NH)NH₂. Amd represents amidino, —C(NH)NH₂, andthe designations (Amd)D-Amf and D-Amf(Amd) are also interchangeably usedfor D-Gmf. The designations Ily and Ior are respectively used to meanisopropyl Lys and isopropyl Orn, wherein the side chain amino group isalkylated with an isopropyl group.

Alkyl means an alkane radical which can be a straight, branched, andcyclic alkyl group such as, but not limited to, methyl, ethyl, propyl,isopropyl, cyclopropyl, butyl, t-butyl, sec-butyl, pentyl, cyclopentyl,hexyl, cyclohexyl, cyclohexylethyl. C₁ to C₈ alkyl refers to alkylgroups having between one and eight carbon atoms. Similarly, C₁-C₆ alkylrefers to alkyl groups having between one and six carbon atoms.Likewise, C₁-C₄ alkyl refers to alkyl groups having between one and fourcarbon atoms. By lower alkyl is meant C₁-C₆ alkyl. Me, Et, Pr, Ipr, Bu,and Pn are interchangeably used to represent the common alkyl groups:methyl, ethyl, propyl, isopropyl, butyl, and pentyl, respectively.Although the linkage for an alkyl group is typically at one end of analkyl chain, the linkage may be elsewhere in the chain, e.g. 3-pentylwhich may also be referred to as ethylpropyl, or 1-ethylprop-1-yl.Alkyl-substituted, such as C₁ to C₆ alkyl-substituted amidino, indicatesthat the relevant moiety is substituted with one or more alkyl groups.

Where a specified moiety is null, the moiety is absent and if suchmoiety is indicated to be attached to two other moieties, such two othermoieties are connected by one covalent bond. Where a connecting moietyis shown herein as attached to a ring at any position on the ring, andattached to two other moieties, such as R₁ and R₂, in the case where theconnecting moiety is specified to be null, then the R₁ and R₂ moietiescan each be independently attached to any position on the ring.

The terms “heterocycle”, “heterocyclic ring” and “heterocyclyl” are usedinterchangeably herein and refer to a ring or ring moiety having atleast one non-carbon ring atom, also called a heteroatom, which can be anitrogen atom, a sulfur atom, or an oxygen atom. Where a ring isspecified as having a certain number of members, the number defines thenumber of ring atoms without reference to any substituents or hydrogenatoms bonded to the ring atoms. Heterocycles, heterocyclic rings andheterocyclyl moieties can include multiple heteroatoms independentlyselected from nitrogen, sulfur, or oxygen atom in the ring. Rings can besubstituted at any available position. For example, but withoutlimitation, 6- and 7-membered rings are often substituted in the 4-ringposition and 5-membered rings are commonly substituted in the3-position, wherein the ring is attached to the peptide amide chain atthe 1-ring position.

The term “saturated” means an absence of double or triple bonds and theuse of the term in connection with rings describes rings having nodouble or triple bonds within the ring, but does not preclude double ortriple bonds from being present in substituents attached to the ring.The term “non-aromatic” in the context of a particular ring refers to anabsence of aromaticity in that ring, but does not preclude the presenceof double bonds within the ring, including double bonds which are partof an aromatic ring fused to the ring in question. Nor is a ring atom ofa saturated heterocyclic ring moiety precluded from being double-bondedto a non-ring atom, such as for instance a ring sulfur atom beingdouble-bonded to an oxygen atom substituent. As used herein,heterocycles, heterocyclic rings and heterocyclyl moieties also includesaturated, partially unsaturated and heteroaromatic rings and fusedbicyclic ring structures unless otherwise specified. A heterocycle,heterocyclic ring or heterocyclyl moiety can be fused to a second ring,which can be a saturated, partially unsaturated, or aromatic ring, whichring can be a heterocycle or a carbocycle. Where indicated, twosubstituents can be optionally taken together to form an additionalring. Rings may be substituted at any available position. A heterocycle,heterocyclic ring and heterocyclyl moiety can, where indicted, beoptionally substituted at one or more ring positions with one or moreindependently selected substituents, such as for instance, C₁-C₆ alkyl,C₃-C₈ cycloalkyl, C₁-C₆ alkoxy, halo C₁-C₆ alkyl, optionally substitutedphenyl, aryl, heterocyclyl, oxo, —OH, —Cl, —F, —NH₂, —NO₂, —CN, —COOHand amidino. Suitable optional substituents of the phenyl substituentinclude for instance, but without limitation, one or more groupsselected from C₁-C₃ alkyl, C₁-C₃ alkoxy, halo C₁-C₃ alkyl, oxo, —OH,—Cl, —F, —NH₂, —NO₂, —CN, —COOH and amidino.

D-Phe and substituted D-Phe are examples of a suitable amino acid forresidue Xaa₁ in Formula I. The phenyl ring can be substituted at any ofthe 2-, 3- and/or 4-positions. Particular examples of permittedsubstitutions include, for instance, chlorine or fluorine at the 2- or4-positions. Also the alpha-carbon atom may be methylated. Otherequivalent residues which represent conservative changes to D-Phe canalso be used. These include D-Ala(cyclopentyl), D-Ala(thienyl), D-Tyrand D-Tic. The residue at the second position, Xaa₂ can also be D-Phe orsubstituted D-Phe with such substitutions including a substituent on the4-position carbon of the phenyl ring, or on both the 3- and 4-positions.Alternatively, Xaa₂ can be D-Trp, D-Tyr or D-alanine substituted bynaphthyl. The third position residue, Xaa₃ can be any non-polar aminoacid residue, such as for instance, D-Nle, D-Leu, (α-Me)D-Leu, D-Hle,D-Met or D-Val. However, D-Ala(cyclopropyl, cyclobutyl, cyclopentyl orcyclohexyl) or D-Phe can also be used as Xaa₃. The fourth positionresidue Xaa₄ can be any positively charged amino acid residue, such asfor instance, D-Arg and D-Har, which can be optionally substituted withlower alkyl groups, such as one or two ethyl groups. Alternatively,D-Nar and any other equivalent residues can be used, such as, forinstance, D-Lys or D-Orn (either of which can be ω-amino groupalkylated, for example by methyl or isopropyl groups, or methylated atthe α-carbon group). Moreover, D-Dbu, D-4-Amf (which can be optionallysubstituted with amidino), and D-Hlys are also suitable amino acids atthis position.

D-amino acid peptides of the invention contain one or more chiralcenters, each of which has two possible three-dimensional spatialarrangements (configurations) of the four substituents around thecentral carbon atom. These are known as “stereoisomers”, and morespecifically as “enantiomers” (all chiral centers inverted) or“diastereoisomers” (two or more chiral centers, at least one chiralcenter remaining the same). In a specific embodiment of the invention,the amino acids which make up the tetrapeptide backbone,Xaa₁Xaa₂Xaa₃Xaa₄ of the kappa opioid receptor agonist peptide amides arespecified to be D-amino acids i.e., the opposite configuration to thosegenerally found in mammals. Reference to stereoisomers of the syntheticpeptide amides of the invention concerns chiral centers other than thealpha carbons of the D-amino acids which make up Xaa₁-Xaa₄. Thus,stereoisomers of synthetic peptide amides that are embodiments of theinvention wherein each of Xaa₁-Xaa₄ are specified to be D-amino acids,do not include L-amino acids or racemic mixtures of the amino acids atthese positions. Similarly, reference to racemates herein concerns acenter other than the alpha carbons of the D-amino acids which make upXaa₁-Xaa₄. Chiral centers in the synthetic peptide amides of theinvention for which a stereoisomer may take either the R or Sconfiguration include chiral centers in the moiety attached to thecarboxy-terminus of Xaa₄, and also chiral centers in any amino acid sidechain substituents of Xaa₁-Xaa₄.

The kappa opioid receptor agonist peptide amides useful in the practiceof the invention described herein can be used or prepared in alternateforms. For example, many amino-containing compounds can be used orprepared as an acid salt. Often such salts improve isolation andhandling properties. For example, depending on the reagents, reactionconditions and the like, compounds such as the kappa opioid receptoragonist peptide amides described herein can be used or prepared, forexample, as the hydrochloride or tosylate salts. Isomorphic crystallineforms, all chiral and racemic forms, N-oxide, hydrates, solvates, andacid salt hydrates, are also contemplated to be within the scope of thepresent invention.

Certain acidic or basic kappa opioid receptor agonist peptide amidesuseful in the practice of the present invention may exist aszwitterions. All forms of these kappa opioid receptor agonist peptideamides, including free acid, free base and zwitterions, are contemplatedto be within the scope of the present invention. It is well known in theart that compounds containing both amino and carboxyl groups often existin equilibrium with their zwitterionic forms. Thus, for any compounddescribed herein that contains, for example, both amino and carboxylgroups, it will also be understood to include the correspondingzwitterion.

As used herein, the chemical designation“tetrapeptide-[ω(4-amino-piperidine-4-carboxylic acid)]” is used toindicate the aminoacyl moiety of the kappa opioid receptor agonistpeptide amides of the invention derived from4-aminopiperidine-4-carboxylic acid, wherein the nitrogen atom of thepiperidine ring is bound to the C-terminal carbonyl-carbon of thetetrapeptide fragment, unless otherwise indicated.

In another embodiment, the amide moiety of the D-amino acid amide(designated as “G” in structural formula I and formula III, below) ischosen from the following groups:

In one embodiment, the invention provides a kappa opioid receptoragonist peptide amide wherein each Xaa₁ is D-Phe, each Xaa₂ is D-Phe,each Xaa₃ is D-Leu and each Xaa₄ is D-Lys. In another embodiment, eachXaa₁ is D-Ala(2-thienyl), each Xaa₂ is D-Phe, each Xaa₃ is D-Nle, andeach Xaa₄ is D-Arg.

In another embodiment each Xaa₄ is chosen from ε(B)₂D-Lys, (B)₂D-Arg,and δ-(B)₂D-Orn. In another particular aspect each Xaa₄ is chosen fromD-Arg, (Et)₂D-Arg, and δ-(B)D-Orn, and (B) is H, Me, iPr, or Bu.

In another embodiment W is null and G is

In another embodiment W is —N—(CH₂)_(b) with b equal to 0, 1, 2, 3, or4. In one aspect b is zero and Y is a carbon atom. In another aspect bis 1 or 2 and Y is a nitrogen atom. In another embodiment W is—N—(CH₂)_(c)—O—. In one particular aspect c is 1 or 2. In another aspectthe Y and Z-containing ring moiety is a four or five membered ring and Yis a nitrogen atom. In another embodiment the Y and Z-containing ringmoiety is a four or five membered ring and Y is a carbon atom.

In another embodiment the Y and Z-containing ring moiety is a six orseven membered ring, Y is nitrogen and Z is a carbon atom. In anotheralternative, the Y and Z-containing ring moiety is a six membered ring.In one aspect the Y and Z-containing ring moiety is a seven memberedring. In still another aspect the Y and Z-containing ring moiety is asix or seven membered ring and both Y and Z are nitrogen atoms.

In another embodiment e is zero and R₁ and R₂ are bonded directly to thesame ring atom. In one aspect e is zero, R₂ is —H and R₁ is bondeddirectly to a carbon ring atom adjacent to Z. In another aspect R₁ is H,amidino, C₁-C₃ alkyl substituted amidino, C₁-C₃ alkyl, dihydroimidazole,D-Pro, D-Pro amide, or —CONH₂ and wherein e is zero and R₂ is —H. Inanother aspect R₁ is —H, amidino, or methyl amidino. In one aspect the Yand Z-containing ring moiety is a five membered ring, e is zero and R₁is —COOH.

In another embodiment G is

and Xaa₁ is D-Phe, Xaa₂ is D-Phe, Xaa₃ is D-Leu, Xaa₄ is ε(B)₂D-Lys, orδ-(B)₂D-Orn, wherein (B) is —H, methyl, or isopropyl; further wherein Wis null, the Y and Z-containing ring moiety is a six or seven memberedring, Y is a nitrogen atom, e is zero, R₁ is —NH₂, amidino, C₁-C₃ alkyl,C₁-C₃ alkyl-substituted amidino, dihydroimidazole, D-Pro, or D-Proamide, and R₂ is H or —COOH.

In one particular embodiment the kappa opioid receptor agonist peptideamide useful in the formulations of the invention has the formula:

wherein G is:

and b is zero and Y is a carbon atom. In another embodiment, b is 1 or 2and Y is a nitrogen atom. In a particular aspect of the invention, b is2.

In another embodiment G is

and the Y- and Z-containing moiety is [ω(4-aminopiperidine-4-carboxylicacid)]-OH.

In one particular embodiment Xaa₁ is chosen from D-Phe, D-(4-F)Phe,D-(2-F)Phe, cyclopentyl D-Ala, 2-thienyl D-Ala, Xaa₂ is chosen fromD-(4-F)Phe, D-(4-Cl)Phe, D-1Nal, D-2Nal, and D-Trp, and Xaa₃-Xaa₄ ischosen from D-Nle-D-Arg and D-Leu-D-Orn.

In another embodiment W is an N-alkoxyl linker of the formula:—N—(CH₂)₂—O—. In an alternative embodiment W is null andXaa₁Xaa₂Xaa₃Xaa₄ is directly bonded to Y. In a second alternativeembodiment, W is —NH—(CH₂)₂—.

Alternatively, and in other embodiments, each instance of one or more ofthe pairs of residues Xaa₁, Xaa₂, Xaa₃ or Xaa₄ can be different. Forexample, one instance of Xaa₁ can be D-phenylalanine, while the secondinstance of Xaa₁ in the same molecule can be a different Xaa₁ residue,such as D-(4-F)phenylalanine. Similarly, one instance of Xaa₂ can beD-phenylalanine, while the second instance of Xaa₂ in the same moleculecan be D-Ala(2-thienyl). Likewise, one instance of Xaa₃ can beD-norleucine, while the second instance of Xaa₃ in the same molecule canbe D-leucine. In the same manner, one instance of Xaa₄ can beD-ornithine, while the second instance of Xaa₄ in the same molecule canbe D-arginine, and so on.

In one embodiment, the invention provides a kappa opioid receptoragonist peptide amide wherein Xaa₁ is D-Ala(2-thienyl). In anotherembodiment Xaa₁ is D-(4-F) phenylalanine and Xaa₂ isD-(4-Cl)phenylalanine. In another embodiment each Xaa₁ isD-phenylalanine or D-Ala(2-thienyl) and each Xaa₂ isD-(4-Cl)phenylalanine. In another embodiment Xaa₁-Xaa₂ isD-phenylalanine-D-phenylalanine.

In one embodiment each Xaa₃ is chosen from D-norleucine and D-leucine.In another embodiment each Xaa₂ is D-phenylalanine, each Xaa₃ isD-norleucine, and each Xaa₄ is D-arginine. In another embodiment eachXaa₃ can be D-leucine or D-norleucine.

In another embodiment Xaa₄ is chosen from δ(B)₂D-ornithine andD-arginine. Alternatively, each Xaa₄ is δ(B)₂D-ornithine and each (B) ischosen from —H, methyl and isopropyl. In still another embodiment, eachXaa₄ is (B)₂D-ornithine, wherein one (B) is —H, and the other (B) chosenfrom methyl and isopropyl. In one aspect, each Xaa₄ is (B)₂D-arginine,or δ-(B)₂D-ornithine. In another embodiment each Xaa₄ can be a residuechosen from D-arginine, (Et)₂D-arginine, and δ-(B)D-ornithine, andwherein (B) is —H, methyl, isopropyl, or butyl. In one embodiment thedipeptide Xaa₃-Xaa₄ is chosen from D-leucine-D-ornithine andD-norleucine-D-arginine.

In another particular embodiment, the Y and Z-containing ring moiety isa four or five membered ring and Y is a nitrogen atom. Alternatively,the Y- and Z-containing ring moiety can be a four or five membered ringwherein Y is a carbon atom. In a different embodiment, the Y andZ-containing ring moiety is a 6- or 7-membered ring, Y is a nitrogenatom and Z is a carbon atom. In one aspect of this embodiment, the Y andZ-containing ring moiety is a 6-membered ring. Alternatively, the Y andZ-containing ring moiety can be a seven membered ring. In one aspect ofthis embodiment, the Y and Z-containing ring moiety is a 6- or7-membered ring and both Y and Z are nitrogen atoms.

In another particular embodiment the Y- and Z-containing ring moiety isa six or seven membered ring, or an eight-membered ring, Y is a carbonatom, and Z is a nitrogen atom. In one aspect, Y is a nitrogen atom andZ is a carbon atom. In an alternative embodiment Y and Z are eachnitrogen atoms.

In another particular embodiment the Y- and Z-containing ring moiety isan optionally substituted 4-, 5-, 6-, 7-, or 8-membered heterocyclicring moiety wherein Y is a carbon or a nitrogen atom and Z is carbon,nitrogen, oxygen, sulfur, sulfoxide, or sulfonyl; and the 4-, 5-, 6-,7-, or 8-membered heterocyclic ring moiety is optionally singly ordoubly substituted with substituents independently chosen from C₁-C₆alkyl, —C₁-C₆ alkoxy, oxo, —OH, —Cl, —F, —NH₂, —NO₂, —CN, —COOH, andamidino. In one aspect when the Y- and Z-containing ring moiety is asix, seven or eight-membered ring, then Y and Z are separated by atleast two ring atoms. In another aspect, when the Y- and Z-containingring moiety is non-aromatic and Z is a carbon or a nitrogen atom, thensuch ring moiety includes at least one sulfur or oxygen ring heteroatom.In a particular aspect, when the Y- and Z-containing ring moiety isaromatic, then Y is a carbon atom.

In one embodiment of the kappa opioid receptor agonist peptide amide ofthe invention, R₁ is —H, —OH, —NH₂, —COOH, C₁-C₃ alkyl, amidino, C₁-C₃alkyl-substituted amidino, dihydroimidazole, D-Pro, D-Pro amide, or—CONH₂. In another particular embodiment R₂ is —H, —COOH, or C₁-C₃alkyl. In one aspect, only one of R₁ and R₂ is a hydrogen atom. In aparticular embodiment R₁ is —H, D-Pro, D-Pro amide, or —NH₂ and R₂ is Hor —COOH. In one aspect of this embodiment, R₁ is —NH₂ and R₂ is —COOH.

In one embodiment, the operator, e is zero and R₁ and R₂ are bondeddirectly to the same ring atom. In a particular embodiment, e is zero,R₂ is —H and R₁ is bonded directly to a carbon ring atom adjacent to Z.In another particular embodiment, R₁ is —H, amidino, C₁-C₃ alkylsubstituted amidino, C₁-C₃ alkyl, dihydroimidazole, D-Pro, D-Pro amide,or —CONH₂ and e is zero and R₂ is —H.

In one embodiment of the kappa opioid receptor agonist peptide amide ofthe invention, Xaa₁ is D-Phe, Xaa₂ is D-Phe, Xaa₃ is D-Leu, Xaa₄ isδ-(B)₂D-Orn, wherein (B) is —H, methyl, or isopropyl; such that whereinW is null, the Y and Z-containing ring moiety is a six or seven memberedring, Y is a nitrogen atom, e is zero, R₁ is —NH₂, amidino, C₁-C₃ alkyl,C₁-C₃ alkyl-substituted amidino, dihydroimidazole, D-Pro, or D-Proamide, and R₂ is H or —COOH.

In one embodiment of the kappa opioid receptor agonist peptide amide ofthe invention: Xaa₁ is chosen from (A) D-Phe, (α-Me)D-Phe, D-Tyr, D-Tic,(tert-butyl)D-Gly, and β-(E)D-Ala, wherein (A) is chosen from —H, —F,—Cl, —NO₂, and —CH₃, and (E) is chosen from tert-butyl, cyclopentyl andthienyl; Xaa₂ is chosen from (A)(A′)D-Phe, D-1Nal, D-2Nal, D-Tyr, andD-Trp, wherein (A′) is H or Cl; Xaa₃ is chosen from D-Nle, D-Phe,(cyclopentyl) D-Ala, D-Leu, (α-Me)D-Leu, D-Hle, D-Val, and D-Met; andXaa₄ is chosen from D-Arg, (ethyl)₂D-Arg, D-Nar, D-Har, (ethyl)₂D-Har,ε-(isopropyl)D-Lys, D-Lys, D-Amf, amidino-D-Amf, β-amidino-D-Dap, D-Dbu,D-Orn, α-(methyl)D-Orn and δ-(isopropyl)D-Orn.

In another embodiment of the kappa opioid receptor agonist peptide amideof the invention: Xaa₁Xaa₂ is D-Phe-D-Phe, Xaa₃ is D-Leu or D-Nle andXaa₄ is chosen from (B)₂D-Arg, D-Lys, (B)₂D-Nar, (B)₂D-Har, ζ-(B)D-Hlys,D-Dap, amidino-D-Dap, ε-(B)D-Lys, ε-(B)₂-D-Lys, D-Amf, amidino-D-Amf,γ-(B)₂D-Dbu and δ-(B)₂α-(B′)D-Orn.

In another embodiment of the kappa opioid receptor agonist peptide amideof the invention: Xaa₄ is chosen from D-Lys, (B)₂D-Har, ε(B)-D-Lys,δ(B)₂.α(B)D-Orn and ε(B)₂-D-Lys.

In another embodiment of the kappa opioid receptor agonist peptide amideof the invention: Xaa₁ is chosen from (A) D-Phe, (α-Me)D-Phe, D-Tyr,D-Tic, (tert-butyl)D-Gly, and β-(E)D-Ala, wherein A is selected from thegroup consisting of —H, —F, —Cl, —NO₂, and —CH₃, and (E) is selectedfrom the group consisting of tert-butyl, cyclopentyl and thienyl; Xaa₂is selected from the group consisting of (A)(A′)D-Phe, D-1Nal, D-2Nal,D-Tyr, and D-Trp, wherein (A′) is H or Cl; Xaa₃ is selected from thegroup consisting of D-Nle, D-Phe, (cyclopentyl)D-Ala, D-Leu,(α-Me)D-Leu, D-Hle, D-Val, and D-Met; and Xaa₄ is selected from thegroup consisting of D-Arg, (ethyl)₂D-Arg, D-Nar, D-Har, (ethyl)₂D-Har,ε-(isopropyl)D-Lys, D-Lys, D-Amf, amidino-D-Amf, β-amidino-D-Dap, D-Dbu,D-Orn, α-(methyl)D-Orn and δ-(isopropyl)D-Orn.

In another embodiment of the kappa opioid receptor agonist peptide amideof the invention: Xaa₁ is D-Phe; Xaa₂ is D-Phe; Xaa₃ is D-Leu and Xaa₄is chosen from D-Nar, D-Orn, and (isopropyl)D-Orn.

In another embodiment of the kappa opioid receptor agonist peptide amideof the invention: L is a linker chosen from ε-D-Lys, δ-Lys, δ-D-Orn,δ-Orn, 4-amino-4-carboxylic piperidine and bis(D-Lys-Gly)Lactam.

In another embodiment of the kappa opioid receptor agonist peptideamide, the Y and Z-containing ring moiety is a six-membered saturatedring. In a particular aspect of this embodiment, the Y and Z-containingring moiety comprises a single heteroatom and e is zero, and R₁ and R₂taken together or with one or two ring atoms of the Y and Z-containingring moiety comprise an optionally substituted monocyclic or bicyclic4-, 5, 6-, 7, 8- or 9-membered heterocyclic ring moiety. In a particularaspect of this embodiment, R₁ and R₂ taken together with one ring atomof the Y and Z-containing ring moiety comprises a five-memberedheterocyclic ring moiety having only heteroatoms chosen from N and O,which heterocyclic ring moiety with the Y and Z-containing ring moietyforms a spiro structure.

In another embodiment of the kappa opioid receptor agonist peptideamide, the Y and Z-containing ring moiety includes two heteroatoms. In aparticular aspect of this embodiment, the two heteroatoms of the Y andZ-containing ring moiety are both nitrogen. In another particular aspectof this embodiment, the integer e is zero, R₂ is hydrogen and the Y- andZ-containing ring moiety is 3-substituted with R₁. In still anotherparticular aspect of this embodiment, the two heteroatoms of the Y- andZ-containing ring moiety are nitrogen and oxygen. In one particularaspect the Y- and Z-containing ring moiety is 3-substituted with R₁, theinteger e is zero and R₂ is hydrogen. In another particular aspect thetwo heteroatoms of the Y- and Z-containing ring moiety are nitrogen andsulfur. In still another particular aspect the Y- and Z-containing ringmoiety is 3-substituted with R₁, e is zero and R₂ is H.

As used herein, a kappa opioid receptor-associated disease, condition ordisorder is any disease, condition or disorder that is preventable ortreatable by activation of a kappa opioid receptor. In some embodiments,a particular oral dose of the formulation of the invention that includesthe kappa opioid receptor agonist peptide amide can be chosen by aclinician to completely prevent or cure the disease, condition ordisorder. In other embodiments a particular oral dose of the formulationof the invention that includes the kappa opioid receptor agonist peptideamide chosen by the clinician ameliorates or reduces one or moresymptoms of the disease, condition or disorder.

As used herein, “effective amount” or “sufficient amount” of the of theformulation of the invention that includes the kappa opioid receptoragonist peptide amide included in the formulation of the inventionrefers to an amount of the formulation as described herein that may betherapeutically effective to inhibit, prevent, or treat a symptom of aparticular disease, disorder, condition, or side effect.

As used herein, “pharmaceutically acceptable” refers to compounds,materials, compositions, and/or dosage forms which are, within the scopeof sound medical judgment, suitable for contact with the tissues ofhuman beings and animals without severe toxicity, irritation, allergicresponse, or other complications, commensurate with a benefit-to-riskratio that is reasonable for the medical condition being treated.

As used herein, “dosage unit” refers to a physically discrete unitsuited as unitary dosages for a particular individual or condition to betreated. Each unit may contain a predetermined quantity of theformulation of the invention comprising the active kappa opioid receptoragonist peptide amide calculated to produce the desired therapeuticeffect(s), optionally in association with a pharmaceutical carrier. Thespecification for the dosage unit forms may be dictated by (a) theunique characteristics of the active kappa opioid receptor agonistpeptide amide, and the particular therapeutic effect to be achieved, and(b) the limitations inherent in the art of compounding such active kappaopioid receptor agonist peptide amide. The dosage unit is oftenexpressed as weight of compound per unit body weight, for instance, inmilligrams of compound per kilogram of body weight of the subject orpatient (mg/kg). Alternatively, the dosage can be expressed as theamount of the compound per unit body weight per unit time, (mg/kg/day)in a particular dosage regimen. In a further alternative, the dosage canbe expressed as the amount of compound per unit body surface area(mg/m²) or per unit body surface area per unit time (mg/m²/day).

As used herein, a “pharmaceutically acceptable salt” refers to aderivative of a compound wherein the parent compound is modified bymaking an acid or a base salt thereof. Examples of pharmaceuticallyacceptable salts include, but are not limited to, mineral or organicacid salts of basic residues such as amines; alkali or organic salts ofacidic residues such as carboxylic acids and the like. Thepharmaceutically acceptable salts include the conventional non-toxicsalts or the quaternary ammonium salts of the parent compound formed,for example, from non-toxic inorganic or organic acids. For instance,such conventional non-toxic salts include those derived from inorganicacids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric,nitric acids and the like; and the salts prepared from organic acidssuch as acetic, propionic, succinic, glycolic, stearic, lactic, malic,tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic,glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric,toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionicacids, and the like. These physiologically acceptable salts are preparedby methods known in the art, e.g., by dissolving the free amine baseswith an excess of the acid in aqueous alcohol, or neutralizing a freecarboxylic acid with an alkali metal base such as a hydroxide, or withan amine. Thus, a pharmaceutically acceptable salt of a syntheticpeptide amide can be formed from any such peptide amide having eitheracidic, basic or both functional groups. For example, a peptide amidehaving a carboxylic acid group, may in the presence of apharmaceutically suitable base, form a carboxylate anion paired with acation such as a sodium or potassium cation. Similarly, a peptide amidehaving an amine functional group may, in the presence of apharmaceutically suitable acid such as HCl, form a salt.

An example of a pharmaceutically acceptable solvate of a kappa opioidreceptor agonist peptide amide is a combination of a peptide amide withsolvent molecules which yields a complex of such solvent molecules inassociation with the peptide amide. Combinations of a drug and propyleneglycol (1,2-propanediol) have been used to form pharmaceutical drugsolvates. See for example U.S. Pat. No. 3,970,651. Other suitablesolvates are hydrates of drug compounds. Such hydrates include hydrateswhich either have comparable activity or hydrates which are convertedback to the active compound following administration. A pharmaceuticallyacceptable N-oxide of a synthetic peptide amide is such a compound thatcontains an amine group wherein the nitrogen of the amine is bonded toan oxygen atom.

A pharmaceutically acceptable crystalline, isomorphic crystalline oramorphous form of a kappa opioid receptor agonist peptide amide usefulin the formulations of the invention can be any crystalline ornon-crystalline form of a pharmaceutically acceptable acidic, basic,zwitterionic, salt, hydrate or any other suitably stable,physiologically compatible form of the kappa opioid receptor agonistpeptide amide according to the invention.

The kappa opioid receptor agonist peptide amide in the formulations ofthe invention can be incorporated into pharmaceutical compositions. Thecompositions can include an effective amount of the kappa opioidreceptor agonist peptide amide in a pharmaceutically acceptable diluent,excipient or carrier. Conventional excipients, carriers and/or diluentsfor use in pharmaceutical compositions are generally inert and make upthe bulk of the preparation. The pharmaceutical excipient or carrier canbe any compatible, non-toxic substance suitable as a vehicle fordelivery the synthetic peptide amide of the invention. Suitableexcipients or carriers include, but are not limited to, sterile water(preferably pyrogen-free), saline, phosphate-buffered saline (PBS),water/ethanol, water/glycerol, water/sorbitol, water/polyethyleneglycol, propylene glycol, cetylstearyl alcohol, carboxymethylcellulose,corn starch, lactose, glucose, microcrystalline cellulose, magnesiumstearate, polyvinylpyrrolidone (PVP), citric acid, tartaric acid, oils,fatty substances, waxes or suitable mixtures of any of the foregoing.

The pharmaceutical composition according to the invention can beformulated as a liquid, semisolid or solid dosage form. For example thepharmaceutical preparation can be in the form of a solution, drops,syrup, spray, suspension, gel, emulsion or in a particulate form, suchas pellets or granules, optionally pressed into tablets or lozenges,packaged in capsules or suspended in a liquid. The tablets can containbinders, lubricants, diluents, coloring agents, flavoring agents,wetting agents and may be enteric-coated to survive the acid environmentof the stomach and dissolve in the more alkaline conditions of theintestinal lumen. Alternatively, the tablets can be sugar-coated or filmcoated with a water-soluble film. Pharmaceutically acceptable adjuvants,buffering agents, dispersing agents, and the like, may also beincorporated into the pharmaceutical compositions.

Binders include for instance, starch, mucilage, gelatin and sucrose.Lubricants include talc, lycopodium, magnesium and calciumstearate/stearic acid. Diluents include lactose, sucrose, mannitol,salt, starch and kaolin. Wetting agents include propylene glycol andsorbitan monostearate.

For oral administration, an active ingredient can be administered insolid dosage forms, such as capsules, tablets, and powders, or in liquiddosage forms, such as elixirs, syrups, and suspensions. Activecomponent(s) can be encapsulated in gelatin capsules together withinactive ingredients and powdered carriers, such as glucose, lactose,sucrose, mannitol, starch, cellulose or cellulose derivatives, magnesiumstearate, stearic acid, sodium saccharin, talcum, magnesium carbonateand the like. Examples of additional inactive ingredients that may beadded to provide desirable color, taste, stability, buffering capacity,dispersion or other known desirable features are red iron oxide, silicagel, sodium lauryl sulfate, titanium dioxide, edible white ink and thelike. Similar diluents can be used to make compressed tablets. Bothtablets and capsules can be manufactured as sustained release productsto provide for continuous release of medication over a period of hours.Compressed tablets can be sugar coated or film coated to mask anyunpleasant taste and protect the tablet from the atmosphere, or entericcoated for selective disintegration in the gastrointestinal tract.Liquid dosage forms for oral administration can contain coloring andflavoring to increase patient acceptance. To facilitate drug stabilityand absorption, peptides of the invention can be released from a capsuleafter passing through the harsh proteolytic environment of the stomach.

The active ingredient may be administered all at once, or may be dividedinto a number of smaller doses to be administered at intervals of time,or as a controlled release formulation. The term “controlled releaseformulation” encompasses formulations that allow the continuous deliveryof a synthetic peptide amide of the invention to a subject over a periodof time, for example, several days to weeks. Such formulations may beadministered subcutaneously or intramuscularly and allow for thecontinual steady state release of a predetermined amount of compound inthe subject over time. The controlled release formulation of kappaopioid receptor agonist peptide amide may be, for example, a formulationof drug containing polymeric microcapsules, such as those described inU.S. Pat. Nos. 4,677,191 and 4,728,721, incorporated herein byreference. The concentration of the pharmaceutically active compound isadjusted so that administration provides an effective amount to producea desired effect. The exact dose depends on the age, weight andcondition of the patient or animal, as is known in the art. For anyparticular subject, specific dosage regimens can be adjusted over timeaccording to the individual need and the professional judgment of theperson administering or supervising the administration of theformulations. Thus, the concentration ranges set forth herein areexemplary only and are not intended to limit the scope or practice ofthe claimed invention.

The compositions can be administered for prophylaxis or treatment ofindividuals suffering from, or at risk of a disease or a disorder.Prophylaxis is defined as a measure designed to preserve the health ofan individual. For therapeutic applications, a pharmaceuticalcomposition is typically administered to a subject suffering from adisease or disorder, in an amount sufficient to inhibit, prevent, orameliorate the disease or disorder. An amount adequate to accomplishthis is defined as a “therapeutically effective dose.”

The pharmaceutical formulations of the invention can be administered toa mammal for prophylactic or therapeutic purposes. The mammal can be anymammal, such as a domesticated or feral mammal, or even a wild mammal.The mammal can be any primate, ungulate, canine or feline. For instance,and without limitation, the mammal may be a pet or companion animal,such as a dog or a cat; a high-value mammal such as a thoroughbred horseor a show animal; a farm animal, such as a cow, a goat, a sheep or pig;or a primate such as an ape, gorilla, orangutan, lemur, monkey orchimpanzee. A suitable mammal for prophylaxis or treatment using thepharmaceutical formulations of the invention is a human.

The pharmaceutical formulations of the invention can be administered toa mammal having a disease or condition treatable by activation of thekappa opioid receptor. Alternatively, the pharmaceutical compositionscan be administered as prophylactics to a mammal having a risk ofcontracting or developing a disease or condition preventable byactivation of the kappa opioid receptor. Diseases or conditions that canbe treated or prevented by administration of the pharmaceuticalcompositions of the invention include, without limitation, any conditionthat can be ameliorated by activation of the kappa opioid receptor,including such conditions as pain, inflammation, pruritus, hyponatremia,hypokalemia, congestive heart failure, liver cirrhosis, nephroticsyndrome, hypertension, edema, ileus, tussis and glaucoma.

In a particular embodiment, the pharmaceutical compositions of theinvention can be co-administered with or can include one or more othertherapeutic compounds or adjuvants, such as but not limited to otheropioids, cannabinoids, antidepressants, anticonvulsants, neuroleptics,antihistamines, acetaminophen, corticosteroids, ion channel blockingagents, non-steroidal anti-inflammatory drugs (NSAIDs), and diuretics,many of which are synergistic in effect with the synthetic peptideamides of the invention.

The invention further provides a method of treating or preventing akappa opioid receptor-associated disease or condition in a mammal,wherein the method includes administering to the mammal a compositioncontaining an effective amount of a kappa opioid receptor agonistpeptide amide in a formulation of the invention. The mammal can be anymammal, such as a domesticated or feral mammal, or even a wild mammal.Alternatively, the mammal can be a primate, an ungulate, a canine or afeline. For instance, and without limitation, the mammal may be a pet orcompanion animal, such as a high-value mammal such as a thoroughbred orshow animal; a farm animal, such as a cow, a goat, a sheep or pig; or aprimate such as an ape or monkey. In one particular aspect, the mammalis a human.

The kappa opioid receptor-associated disease, disorders or conditionpreventable or treatable with the kappa opioid receptor agonist peptideamide in a formulation of the invention can be any kappa opioidreceptor-associated condition, including but not limited to acute orchronic pain, inflammation, pruritus, hyponatremia, edema, ileus, tussisand glaucoma. For instance, the kappa opioid receptor-associated paincan be neuropathic pain, somatic pain, visceral pain or cutaneous pain.Some diseases, disorders, or conditions are associated with more thanone form of pain, e.g., postoperative pain can have any or all ofneuropathic, somatic, visceral, and cutaneous pain components, dependingupon the type and extent of surgical procedure employed.

The kappa opioid receptor-associated inflammation can be anyinflammatory disease or condition including, but not limited tosinusitis, rheumatoid arthritis tenosynovitis, bursitis, tendonitis,lateral epicondylitis, adhesive capsulitis, osteomyelitis,osteoarthritic inflammation, inflammatory bowel disease (IBD), irritablebowel syndrome (IBS), ocular inflammation, otitic inflammation orautoimmune inflammation.

The kappa opioid receptor-associated pruritus can be any pruriticdisease or condition such as, for instance, ocular pruritus (usedinterchangeably with the term pruritis), e.g., associated withconjunctivitis, otitic pruritus, pruritus associated with end-stagerenal disease also known as uremic pruritus, where many patients arereceiving kidney dialysis, and other forms of cholestasis, includingprimary biliary cirrhosis, intrahepatic cholestasis of pregnancy,chronic cholestatic liver disease, uremia, malignant cholestasis,jaundice, as well as dermatological conditions such as eczema(dermatitis), including atopic or contact dermatitis, psoriasis,polycythemia vera, lichen planus, lichen simplex chronicus, pediculosis(lice), thyrotoxicosis, tinea pedis, urticaria, scabies, vaginitis, analpruritus associated with hemorrhoids and, as well as insect bitepruritus and drug-induced pruritus, such as mu opioid-induced pruritus.

The kappa opioid receptor-associated edema can be any edematous diseaseor condition such as, for instance, edema due to congestive heartdisease or to a syndrome of inappropriate antidiuretic hormone (ADH)secretion. Kappa opioid receptor-associated ileus can be any ileusdisease or condition including, but not limited to, post-operative ileusand opioid-induced bowel dysfunction. Kappa opioid receptor-associatedneuropathic pain can be any neuropathic pain, such as, for instance,trigeminal neuralgia, diabetic pain, viral pain such as herpeszoster-associated pain, chemotherapy-induced pain, nerve-encroachingmetastatic cancer pain, neuropathic pain associated with traumaticinjury and surgical procedures, as well as variants of headache painthat are thought to have a neuropathic component, e.g., migraine.

Kappa opioid-associated pain also includes ocular pain, such as thatfollowing photo-refractive keratectomy (PRK), ocular laceration, orbitalfloor fracture, chemical burns, corneal abrasion or irritation, or painassociated with conjunctivitis, corneal ulcers, scleritis, episcleritis,sclerokeratitis, herpes zoster ophthalmicus, interstitisal keratitis,acute iritis, keratoconjunctivitis sicca, orbital cellulites, orbitalpseudotumor, pemphigus, trachoma or uveitis.

Kappa opioid-associated pain also includes throat pain, particularlyassociated with inflammatory conditions, such as allergic rhinitis,acute bronchitis, the common cold, contact ulcers, herpes simplex virallesions, infectious mononucleosis, influenza, laryngeal cancer, acutelaryngitis, acute necrotizing ulcerative gingivitis, peritonsillarabscess, pharyngeal burns, pharyngitis, reflus laryngopharyngitis, acutesinusitis, and tonsillitis.

In addition, kappa opioid receptor-associated pain can be arthriticpain, kidney-stone, urinary tract stone, gallstone, and bile duct stonepain, dysmenorrhea, uterine cramping, endometriosis, mastitis,dyspepsia, post-surgical pain (such as, for instance, from appendectomy,open colorectal surgery, hernia repair, prostatectomy, colonicresection, gastrectomy, splenectomy, colectomy, colostomy, pelviclaparoscopy, tubal ligation, hysterectomy, vasectomy orcholecystectomy), post medical procedure pain (such as, for instance,after colonoscopy, cystoscopy, hysteroscopy or cervical or endometrialbiopsy), otitic pain, breakthrough cancer pain, and pain associated witha GI disorder such as IBD or IBS or other inflammatory conditions,particularly of the viscera (e.g., gastro-esophageal reflux disease,pancreatitis, acute polynephritis, ulcerative colitis, acutepyelo-nephritis, cholecystitis, cirrhosis, hepatic abscess, hepatitis,duodenal or gastric ulcer, esophagitis, gastritis, gastroenteritis,colitis, diverticulitis, intestinal obstruction, ovarian cyst, pelvicinflammatory disease, perforated ulcer, peritonitis, prostatitis,interstitial cystitis), or exposure to toxic agents, such as insecttoxins, or inflammation due to the effects of drugs such as salicylatesor NSAIDs.

The present invention provides a method of treating or preventing akappa opioid receptor-associated disease or condition in a mammal, suchas a human, wherein the method includes administering to the mammal aformulation of the invention comprising an effective amount of a kappaopioid receptor agonist peptide amide, and an absorption enhancer of theinvention. In another embodiment the kappa opioid receptor-associatedcondition is pain, inflammation (such as rheumatoid arthriticinflammation, osteoarthritic inflammation, IBD inflammation, IBSinflammation, ocular inflammation, otitic inflammation or autoimmuneinflammation), pruritus (such as atopic dermatitis,kidney-dialysis-associated pruritus, ocular pruritus, otitic pruritus,insect bite pruritus, or opioid-induced pruritus), edema, ileus, tussisor glaucoma. In one aspect, the pain is a neuropathic pain (such astrigeminal neuralgia, migraine, diabetic pain, viral pain,chemotherapy-induced pain or metastatic cancer pain), a somatic pain, avisceral pain or a cutaneous pain. In another aspect the pain isarthritic pain, kidney-stone pain, uterine cramping, dysmenorrhea,endometriosis, dyspepsia, post-surgical pain, post medical procedurepain, ocular pain, otitic pain, breakthrough cancer pain or painassociated with a GI disorder, such as IBD or IBS. In another aspect thepain is pain associated with surgery, wherein the surgery is pelviclaparoscopy, tubal ligation, hysterectomy and cholecystecomy.Alternatively, the pain can be pain associated with a medical procedure,such as for instance, colonoscopy, cystoscopy, hysteroscopy orendometrial biopsy. In a specific aspect, the atopic dermatitis can bepsoriasis, eczema or contact dermatitis. In another specific aspect, theileus is post-operative ileus or opioid-induced bowel dysfunction.

Another form of kappa opioid receptor-associated pain treatable orpreventable with the synthetic peptide amides of the invention ishyperalgesia. In one embodiment, the method includes administering aneffective amount of a synthetic peptide amide of the invention to amammal suffering from or at risk of developing hyperalgesia to prevent,ameliorate or completely alleviate the hyperalgesia.

Kappa opioid receptor-associated pain includes hyperalgesia, which isbelieved to be caused by changes in the milieu of the peripheral sensoryterminal occur secondary to local tissue damage. Tissue damage (e.g.,abrasions, burns) and inflammation can produce significant increases inthe excitability of polymodal nociceptors (C fibers) and high thresholdmechanoreceptors. This increased excitability and exaggerated responsesof sensory afferents is believed to underlie hyperalgesia, where thepain response is the result of an exaggerated response to a stimulus.The importance of the hyperalgesic state in the post-injury pain statehas been repeatedly demonstrated and appears to account for a majorproportion of the post-injury/inflammatory pain state.

In another embodiment the kappa opioid receptor-associated condition ispain, inflammation (such as rheumatoid arthritic inflammation,osteoarthritic inflammation, IBD inflammation, IBS inflammation, ocularinflammation, otitic inflammation or autoimmune inflammation), pruritus(such as atopic dermatitis, kidney-dialysis-associated pruritus, ocularpruritus, otitic pruritus, insect bite pruritus, or opioid-inducedpruritus), edema, ileus, tussis or glaucoma. In one aspect, the pain isa neuropathic pain (such as trigeminal neuralgia, migraine, diabeticpain, viral pain, chemotherapy-induced pain or metastatic cancer pain),a somatic pain, a visceral pain or a cutaneous pain. In another aspectthe pain is arthritic pain, kidney-stone pain, uterine cramping,dysmenorrhea, endometriosis, dyspepsia, post-surgical pain, post medicalprocedure pain, ocular pain, otitic pain, breakthrough cancer pain orpain associated with a GI disorder, such as IBD or IBS. In anotheraspect the pain is pain associated with surgery, wherein the surgery ispelvic laparoscopy, tubal ligation, hysterectomy and cholecystecomy.Alternatively, the pain can be pain associated with a medical procedure,such as for instance, colonoscopy, cystoscopy, hysteroscopy orendometrial biopsy. In a specific aspect, the atopic dermatitis can bepsoriasis, eczema or contact dermatitis. In another specific aspect, theileus is post-operative ileus or opioid-induced bowel dysfunction.

In another embodiment the kappa opioid receptor-associated condition isa kappa opioid receptor-associated condition preventable or treatable bysodium and potassium-sparing diuresis, also known as aquaresis. Anexample of such kappa opioid receptor-associated conditions preventableor treatable by administering a kappa opioid receptor agonist peptideamide in the formulation of the invention includes edema. The edema maybe due to any of a variety of diseases or conditions, such as congestiveheart disease or syndrome of inappropriate ADH secretion.

In another embodiment the kappa opioid receptor-associated condition ishyponatremia or other edematous disease. The kappa opioidreceptor-associated hyponatremia or edema can be any hyponatremic oredematous disease or condition such as, for instance, hyponatremia andedema associated with congestive heart failure or to a syndrome ofinappropriate antidiuretic hormone (ADH) secretion, or hyponatremia thatis associated with intensive diuretic therapy with thiazides and/or loopdiuretics. The synthetic peptide amides of the invention exhibit asignificant sodium-sparing and potassium-sparing aquaretic effect, whichis beneficial in the treatment of edema-forming pathological conditionsassociated with hyponatremia and/or hypokalemia. Accordingly, thesynthetic peptide amides of the invention also have utility in methodsof treating or preventing hyponatremia-related conditions, examples ofwhich are provided below. Hyponatremia-related conditions can becategorized according to volume status as hypervolemic, euvolemic, orhypovolemic.

Hypervolemic hyponatremia is usually caused by an increase in total bodywater level as may be observed in cases of congestive heart failure,nephrotic syndrome and hepatic cirrhosis. Euvolemic hyponatremia isoften found in the syndrome of inappropriate antidiuretic hormone (ADH)secretion and may also be associated with pneumonia, small-cell lungcancer, polydipsia, cases of head injury, and organic causes (e.g., useof certain drugs, such as haloperidol) or a psychogenic cause.Hypovolemic hyponatremia is due to a relative decrease in total bodysodium level and may be associated with, for instance and withoutlimitation, diuretic use, cases of interstitial nephritis or excessivesweating.

The kappa opioid receptor-associated hyponatremia can be any disease orcondition where hyponatremia (low sodium condition) is present, e.g., inhumans, when the sodium concentration in the plasma falls below 135mmol/L, an abnormality that can occur in isolation or, more frequently,as a complication of other medical conditions, or as a consequence ofusing medications that can cause sodium depletion.

In addition to these conditions, numerous other conditions areassociated with hyponatremia including, without limitation: neoplasticcauses of excess ADH secretion, including carcinomas of lung, duodenum,pancreas, ovary, bladder, and ureter, thymoma, mesothelioma, bronchialadenoma, carcinoid, gangliocytoma and Ewing's sarcoma; infections suchas: pneumonia (bacterial or viral), abscesses (lung or brain),cavitation (aspergillosis), tuberculosis (lung or brain), meningitis(bacterial or viral), encephalitis and AIDS; vascular causes such as:cerebrovascular occlusions or hemorrhage and cavernous sinus thrombosis;neurologic causes such as: Guillain-Barre syndrome, multiple sclerosis,delirium tremens, amyotrophic lateral sclerosis, hydrocephalus,psychosis, peripheral neuropathy, head trauma (closed and penetrating),CNS tumors or infections and CNS insults affecting hypothalamicosmoreceptors; congenital malformations including: agenesis of corpuscallosum, cleftlip/palate and other midline defects; metabolic causessuch as: acute intermittent porphyria, asthma, pneurothorax andpositive-pressure respiration; drugs such as: thiazide diuretics,acetaminophen, barbiturates, cholinergic agents, estrogen, oralhypoglycemic agents, vasopressin or desmopressin, high-dose oxytocin,chlorpropamide, vincristine, carbamezepine, nicotine, phenothiazines,cyclophosphamide, tricyclic antidepressants, monoamine oxidaseinhibitors and serotonin reuptake inhibitors; administration of excesshypotonic fluids, e.g., during hospitalization, surgery, or during orafter athletic events (i.e., exercise-associated hyponatremia), as wellas use of low-sodium nutritional supplements in elderly individuals.

Other conditions associated with hyponatremia incude renal failure,nephrotic syndrome (membranous nephropathy and minimal change disease),cachexia, malnutrition, rhabdomyolysis, surgical procedures, electivecardiac catheterization, blood loss, as well as hypercalcemia,hypokalemia, and hyperglycemia with consequent glycosuria leading toosmotic diuresis.

The invention also provides a method of treating or preventing aneuro-degenerative disease or condition in a mammal, such as a human,wherein the method includes administering to the mammal a formulationthat includes an effective amount of a kappa opioid receptor agonistpeptide amide and an absorption enhancer as described above. Theneurodegenerative disease or condition can be any neurodegenerativedisease or condition, such as for instance, ischemia, anoxia, stroke,brain injury, spinal cord injury or reperfusion injury. Alternatively,the neurodegenerative disease or condition can be a neurodegenerativedisease of the eye. Particular neurodegenerative diseases of the eyetreatable or preventable by the method of the invention includeglaucoma, macular degeneration, retinal ischemic disease and diabeticneuropathy.

In certain embodiments the invention provides methods of prevention ortreatment of certain neuronal diseases and conditions, such as diseasesand conditions having a neurodegenerative component. Synthetic peptideamides of the invention can be administered in an amount effective toprotect neuronal cells against the effects of pathology or injury thatwould lead to neurodegeneration and/or neuronal cell death of theuntreated cells. Progression of these diseases and conditions isbelieved to involve neurodegeneration or neuronal cell death, forexample by programmed cell death (apoptosis) in which the neuronal cellsare committed to a pathway that without intervention would lead to celldeath. It has been found that development or progression of thesediseases and conditions can be prevented, or at least slowed, bytreatment with kappa opioid receptor agonists.

In other embodiments the invention provides methods of prevention ortreatment of certain cardiovascular diseases and conditions having acellular degenerative component. Formulations comprising a kappa opioidreceptor agonist peptide amide and an absorption enhancer of theinvention can be administered in an amount effective to protectmyocardial cells against the effects of pathology or injury that wouldlead to degeneration and/or cell death of the untreated cells. Forexample, several cardiovascular diseases or conditions can be preventedor treated by administration of an effective amount of the formulationsof the invention. Such cardiovascular diseases and conditions include,without limitation, coronary heart disease, ischemia, cardiac infarct,reperfusion injury and arrhythmia.

Diseases and conditions of other tissues and organs that can beprevented or treated by administration of an effective amount of thesynthetic peptide amides of the invention include, but are not limitedto ischemia, anoxia, stroke, brain or spinal cord injury and reperfusioninjury.

The invention also provides a bioactive composition that includes abiologically active peptide embedded in an oligomeric saccharide forminga particle including the stabilized biologically active peptide. In oneembodiment the bioactive composition that includes a biologically activepeptide embedded in an oligomeric saccharide forming a particleincluding the stabilized biologically active peptide also includes oneor more of the following: a salt of a carboxylic acid, an absorptionenhancer, a binding agent, a chelating agent and a pharmaceuticallyacceptable carrier or excipient. The salt of a carboxylic acid can beany suitable salt of a carboxylic acid, such as but not limited tosodium citrate. The absorption enhancer can be any suitable absorptionenhancer, such as for instance, lauroyl L-carnitine. The binding agentcan be any suitable binding agent to promote cohesiveness, such ascellulose, methyl or ethyl cellulose, starch, gelatin, PVP, PEG,polyvinyl alcohols and polymethacrylates. The chelating agent, can beany suitable chelating agent such as, and without limitation, succinicacid or EDTA. Commonly used pharmaceutically acceptable carriers orexcipients include calcium salts, such as calcium chloride, calciumphosphate and calcium sulfate; metallic oxides, sugars, sugar alcoholsand sweeteners to name a just few of those well known in the art.

The biologically active peptide can be any suitable a biologicallyactive peptide, such as, and without limitation, a kappa opioid receptoragonist peptide. In one embodiment the a kappa opioid receptor agonistpeptide can be a D-amino acid tetrapeptide amide as described in U.S.Pat. Nos. 7,402,564, 7,713,937 and 7,842,662.

In one embodiment, the D-amino acid tetrapeptide amide is the kappaopioid receptor agonist compound:D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopiperidine-4-carboxylic acid)]-0H alsoreferred to in the literature as CR845 (difelikefalin).

The oligomeric saccharide in which the biologically active peptide isembedded can be any suitable oligomeric saccharide, such as for instancean oligomeric saccharide such as a disaccharide. In one embodiment thedisaccharide may include a glucose monomer such as dextrose. In anotherembodiment the disaccharide may be a glucose dimer such as trehalose.

In one embodiment the biologically active peptide is a tetrapeptideamide kappa opioid receptor agonist embedded in a composition comprisingtrehalose to form a particle comprising a stabilized biologically activepeptide, wherein the particles have an average diameter of from about 2microns to about 100 microns. In another embodiment the particles havean average diameter of from about 5 microns to about 50 microns.

In another embodiment, the invention further provides a bioactivecomposition that includes a biologically active peptide embedded in anoligomeric saccharide forming a particle including the stabilizedbiologically active peptide, wherein the particle is dispersed in aliquid suspension that includes one or more medium chain fatty acids orone or more salts of a medium chain fatty acid and a medium chain fattyacid glyceride. In one embodiment the liquid suspension includes amedium chain fatty acid (C₆-C₁₂ fatty acid). In another embodiment, theliquid suspension includes a medium chain (C₈-C₁₂) fatty acid. In afurther embodiment the liquid suspension includes a medium chain(C₆-C₁₂) fatty acid triglyceride. In another embodiment the liquidsuspension includes a medium chain (C₈-C₁₂) fatty acid triglyceride.

In one embodiment, the liquid suspension suspension including theparticle formed from the biologically active peptide embedded in anoligomeric saccharide includes at least one (C₆-C₁₂) fatty acid and atleast one (C₆-C₁₂) fatty acid triglyceride. The (C₆-C₁₂) chain fattyacid can be a (C₈-C₁₂) fatty acid and the (C₆-C₁₂) chain fatty acidtriglyceride can be a (C₈-C₁₂) fatty acid triglyceride. The (C₈-C₁₂)fatty acid and the (C₆-C₁₂) chain fatty acid triglyceride can be a(C₈-C₁₂) fatty acid triglyceride can be a Miglyol® such as for instanceMiglyol® 812. The suspension can also include one or more of anemulsifying agent, a salt of a carboxylic acid, an absorption enhancer,a binding agent and a pharmaceutically acceptable carrier or excipient.

In another embodiment, the invention provides a bioactive compositionthat includes a biologically active peptide, such as the kappa opioidreceptor agonist, CR845 embedded in an oligomeric saccharide forming aparticle including the stabilized biologically active peptide, whereinthe oligomeric saccharide includes a disaccharide such as trehalose, the1,1-α-glycoside linked glucose dimer. Such trehalose/CR845 particles areuseful as medicinal dry powders, incorporated into blends of medicinaldry powders, or compressed into tablets with solid absorption enhancers,such as lauroyl L-carnitine, and/or citric acid amongst many otherwell-known absorption enhancers without the use of a medium chain fattyacid, salt of a medium chain fatty acid or a medium chain fatty acidglyceride.

The invention further provides a bioactive composition including abiologically active peptide embedded in an oligomeric saccharideparticle to form a stabilized biologically active peptide particle,wherein the oligomeric saccharide enhances the stability of thebiologically active peptide over at least a year at 25° C. In oneembodiment, the biologically active peptide is a kappa opioid receptoragonist comprising one or more D-amino acids and the oligomericdisaccharide comprises glucose. The kappa opioid receptor agonistcomprising one or more D-amino acids can be any suitable kappa opioidreceptor agonist, such as a tetrapeptide amide kappa opioid receptoragonist, such as for instance CR845 and the oligomeric disaccharidecomprising glucose can be for instance, and without limitation,trehalose.

The bioactive composition of the invention including a biologicallyactive peptide embedded in an oligomeric saccharide particle can beincluded in a pharmaceutically acceptable tablet, caplet, capsule,powder, or liquid suspension for administration as a medicament. Thepharmaceutically acceptable tablet, caplet, capsule, powder, or liquidsuspension may further include one or more of a salt of a carboxylicacid, an absorption enhancer, a binding agent and a pharmaceuticallyacceptable carrier or excipient. In one embodiment the pharmaceuticallyacceptable tablet, caplet, capsule, powder, or liquid suspension mayinclude sodium citrate as the carboxylic acid. In another embodiment thepharmaceutically acceptable tablet, caplet, capsule, powder, or liquidsuspension may include lauroyl L-carnitine as an absorption enhancer.

In a further embodiment, the pharmaceutically acceptable tablet, caplet,capsule, powder, or liquid suspension may include CR845 as the a kappaopioid receptor agonist biologically active peptide embedded in anoligomeric saccharide in the form of stabilized particles having adiameter of about 50 microns. In some embodiments, the oligomericsaccharide is a glucose-containing oligomeric saccharide, such astrehalose.

The formulations including the kappa opioid receptor agonist peptideamides and absorption enhancers of the invention can be administered bymethods disclosed herein for the treatment or prevention of anyhyperalgesic condition, such as, but without limitation, a hyperalgesiccondition associated with allergic dermatitis, contact dermatitis, skinulcers, inflammation, rashes, fungal irritation and hyperalgesicconditions associated with infectious agents, burns, abrasions, bruises,contusions, frostbite, rashes, acne, insect bites/stings, skin ulcers,mucositis, gingivitis, bronchitis, laryngitis, sore throat, shingles,fungal irritation, fever blisters, boils, Plantar's warts, surgicalprocedures or vaginal lesions.

Moreover, the formulations including the kappa opioid receptor agonistpeptide amides and absorption enhancers of the invention can beadministered by methods disclosed herein for the treatment or preventionof any hyperalgesic condition associated with burns, abrasions, bruises,abrasions (such as corneal abrasions), contusions, frostbite, rashes,acne, insect bites/stings, skin ulcers (for instance, diabetic ulcers ora decubitus ulcers), mucositis, inflammation, gingivitis, bronchitis,laryngitis, sore throat, shingles, fungal irritation (such as athlete'sfoot or jock itch), fever blisters, boils, Plantar's warts or vaginallesions (such as vaginal lesions associated with mycosis or sexuallytransmitted diseases).

Hyperalgesic conditions associated with post-surgery recovery can alsobe addressed by administration of formulations including the kappaopioid receptor agonist peptide amides and absorption enhancers of theinvention. The hyperalgesic conditions associated with post-surgeryrecovery can be any hyperalgesic conditions associated with post-surgeryrecovery, such as for instance, radial keratectomy, tooth extraction,lumpectomy, episiotomy, laparoscopy and arthroscopy. Hyperalgesicconditions associated with inflammation can also be addressed byadministration of formulations including the kappa opioid receptoragonist peptide amides and absorption enhancers of the invention.

EXAMPLES

The following listing of D-amino acid peptide amides listed as compounds(1)-(103) can be used in the formulations of the present invention:

D-Amino Acid Peptide Amides

Examples (1)-(103)

EXAMPLES 1-105: Synthesis of compounds (1)-(105) has been described: SeeU.S. Pat. Nos. 7,402,564 and 7,713,937 the entire disclosures of whichare incorporated by reference herein.

Example 106: Production of Enterically Coated Size 2 HydroxypropylmethylCellulose (HPMC) Capsules Containing 5 mg CR845 Suspended in 1 g 10%Capric Acid in Miglyol® Solution

Miglyol® 812N (44.750 g) was added in a 50 ml glass beaker. Then 5.00 gcapric acid was weighed and added to the Miglyol® while stirring on amagnetic stir plate with a 0.5 inch stir bar. The mixture wascontinuously stirred at a gentle speed. 0.25 g CR845 was weighed(adjusted for peptide content) and added to the Capric Acid/Miglyol®solution while mixing to produce a uniformly dispersed suspension.Mixing was maintained at 500 rpm throughout the capsule filling processperformed as follows:

A size “2” capsule plate was set up according to the ProCoater CapsuleFiller (Torpac Inc, Fairfield, N.J.) instruction manual with emptycapsule bodies. Using a positive displacement pipette, 0.32 mL of thesuspension was dispensed into each capsule body in the plate.Individually the opened end of each capsule cap was wetted with 90%Ethanol and snapped on each of the filled capsule bodies in the coatingplate. The coating plate with the capsules (cap up) was placed in theDrying Stand and allowed to stand for a minimum of 60 minutes.

Preparation of Enteric Coating Solution

Acetone NF (888 mL) was measured, poured into a 1 L beaker and stirringinitiated. Once a gentile vortex was achieved 120 g Eudragit® L100-55was added to the acetone while mixing. 12 g Triethyl citrate USP wasthen added to the acetone/Eudragit® L100-55 followed by addition of 19.2g water USP to the Acetone/Eudragit® L100-55/Triethyl Citrate whilecontinuously stirring until the solution was clear. The solution wasthen transferred into a 1 L serum bottle and capped.

Application of Enteric Coating Material

Coating solution (200 g) was transferred into the ProCoater CapsuleFiller coating pan and the bodies of the filled capsules were dipped inthe plate in the coating solution, remove and rotate according to theinstructions in the manufacturer's manual. The plate with the coatedcapsules was placed in the ProCoater Capsule Filler Drying Stand andallowed to dry for a minimum of 25 minutes. The capsule holder wasadjusted to expose the capsule caps according to ProCoater manualdirections. The cap of each of the capsules was dipped in each plate inthe coating solution, removed and rotated as per the manufacturer'sinstructions. The plate with the coated capsules was then placed in theProCoater Capsule Filler Drying Stand and dry for a minimum of 25minutes. Additional coating solution was then added to the coating panto maintain appropriate volume and the above steps were repeated torecoat the capsules.

The middle 32 capsules of each plate were transferred into an HDPEbottle (75 mL) labeled with Lot #, date, initials, and number ofcapsules for PK studies. The outside 28 capsules of each plate weretransferred into the HDPE bottle (75 mL) labeled with Lot #, date,initials, and number of capsules and marked “For research stability useonly.”

Example 107: Production of Enterically Coated Size 2 HPMC CapsulesContaining 5 mg

CR845 suspended in 1 g 30% Capric Acid in Miglyol® Solution Miglyol®(34.75 g) and capric acid (15.0 g) were added to a 50 ml glass beakerwhile stirring until a clear solution is obtained. CR845 (0.25 g) wasadded to the capric acid/Miglyol® solution while mixing produce auniformly dispersed suspension. Capsule plate set up, capsule fillingwith the 5 mg CR845 suspended in 1 g 30% capric acid/Miglyol® Solutionand application of the enteric coating material were performed asdescribed above.

Example 108: Oral Administration of Dosing Formulations in Canines

The test formulation was delivered orally within a capsule in a singledose. Capsules were lubricated with reverse osmosis water immediatelyprior to administration. Animals were gently stroked along the neck tostimulate the swallowing reflex after dosing. Immediately after dosing,5-10 mL of reverse osmosis water was administered to the animal. Theoral cavity was inspected following the water flush to ensure that thecapsule had been swallowed.

Example 109: Pharmacokinetic Data from Oral Administration of DosingFormulations in Canines

FIG. 1 shows CR845.HCl acid salt bioavailability measured in cohorts ofeight animals for each of the formulations delivered inenterically-coated size 2 HPMC capsules prepared as described above.Each capsule of prototype formulation 1 contained: 1.6 mg spray driedCR845 in 90% Miglyol 812, 10% sodium caprate. Each capsule of prototypeformulation 2 contained: 1.6 mg crystallized CR845 in 90% Miglyol 812,10% sodium caprate. Each capsule of prototype formulation 3 contained:1.6 mg spray dried CR845 in 90% Miglyol 812, 10% capric acid. Eachcapsule of prototype formulation 4 contained: 1.6 mg spray dried CR845in 70% Miglyol 812 in 30% capric acid. Bioavailability (%f) is expressedas a per cent of CR845 observed (calculated from the area under thecurve: AUC) as compared with the total CR845 AUC observed afterintravenous delivery of the same dose. Composite IV data from fiveseparate studies with thirty-six canines was averaged and used forbioavailability calculations. Ten kilogram dogs were dosed administeredan average dose of 0.029±0.007 mg/kg and the average bioavailability wasset as 100%. The observed avg. Cmax was 163.1±39.2 for comparisonpurposes.

Bioavailability of CR845 as shown used herein are calculated as follows:

${\%\mspace{14mu} f} = {\frac{\left( {{AUC}\mspace{14mu}{ora}\text{l/D}{ose}\mspace{14mu}{oral}} \right)}{\left( {{AUC}\mspace{14mu} i{\text{v}\text{/D}}{ose}\mspace{14mu}{iv}} \right)} \times 100}$

Example 110: Prototype Formulation Dissolution Profiles

FIGS. 2-5 and Table 1 below show the results of capsule dissolutionstudies of capsules containing prototype formulations 1-4 carried outaccording to US Pharmacopeia for Delayed Release Dosage Forms (USP<711>).

TABLE 1 Prototype T for 50% dissolution in Buffer Phase (min)Formulation 1 28.0 Formulation 2 44.1 Formulation 3 31.8 Formulation 427.9

Example 111: Bioactivity of Trehalose-Embedded CR845 Salt PrototypeFormulations

Spray dried particles of CR845 acetate/trehalose/citric acid(9.8/88.2/2.2% w/w) and CR845.HCl/trehalose (23/77% w/w) were filledinto intrinsically enteric (acid resistant) HPMC capsules andadministered to cohorts of eight canines. Citric acid added to theacetate salt was to balance the pH. Average bioavailability for eachformulation was determined as described above and shown in Table 2below:

TABLE 2 Formulation % f SEM CR845 acetate/trehalose/citric acid 4.493.23 CR845•HCl/trehalose 9.40 6.75

Example 112: Bioactivity of Spray Dried Trehalose Embedded CR845.HClFormulations

Formulations 5, 6 and 7 in Size 1 LiCap (Capsugel) enterically coatedcapsules were each administered to a cohort of eight 8 kg canines.Formulation 5 contained 4.0 mg CR845.HCl, 20% capric acid in Miglyol®812N; formulation 6 contained 4.0 mg CR845.HCl, 10% capric acid inMiglyol® 812N; formulation 7 contained 4.0 mg CR845.HCl, 5% capric acidin Miglyol® 812N.

FIGS. 6-8 show PK profiles for formulations 5-7 and averagebioavailability data were calculated from these curves and shown inTable 3 below:

TABLE 3 Formulation % f Std. Dev. SEM 5 12.6 5.79 2.05 6 13.8 9.49 3.367 11.1 9.37 3.31Further studies were performed with CR845.HCl/trehalose formulations.

Example 113: Stability of Prototype Formulations Suspended in Miglyol orCapric Acid

In a first sample study 2.5 mg spray dried particles of CR845 embeddedin trehalose were suspended in 1 gm Miglyol® (A) or 10% capric acid inMiglyol® (B). In a another sample study, 2.5 mg spray dried particles ofCR845 embedded in trehalose/Na caprate/EDTA were suspended in 1 gmMiglyol® (C) or 10% capric acid in Miglyol® (D). Suspensions prepared atroom temperature were assayed for CR845 content and purity. Thesuspensions were then stored at 40° C., 75% rel. humidity and assayedagain at two month and three months to assess stability.Results are shown in Table 4 below:

TABLE 4 2 months 3 months Suspension Initial (40° C./ (40° C./Composition (RT) 75% RH) 75% RH) Capric Con- Pu- Con- Pu- Con- Pu- acidConc. tent rity tent rity tent rity (%) (mg/g) (mg) (%) (mg) (%) (mg)(%) A 0 2.47 2.43 98.10 2.67 98.64 2.65 98.73 B 10 2.47 2.61 98.42 2.6499.00 2.80 98.47 C 0 2.46 1.98 98.24 2.07 98.70 2.03 98.50 D 10 2.462.22 98.10 2.06 97.50 2.04 96.13

Essentially no loss of CR845 content or purity assayed by HPLC was seenafter two or three months storage at 40° C./75% RH. TheCR845/trehalose/Na caprate particles suspended in Miglyol® did notsettle after two months under these conditions. Suspensions were alsovery stable and although settling occurred during storage in othersuspensions, the particles readily resuspended upon inversion.

FIG. 9 upper panel shows suspensions after two months storage and aftertwo months storage followed by thirty inversions. No polymorphic changeswere observed and the particle size distribution of the CR845 embeddedin trehalose also remained stable after one and two months of storage at40° C./75% RH as shown by microscopic examination: FIG. 9 lower panel.

Example 114: Pharmacokinetics of CR845 Formulations Administered inTrehalose-Embedded Particles of CR845.HCl Suspended in Miglyol® 812N

Bioactivity of formulations 8-12 were determined as described above.Compositions of the formulations are shown in Table 5 below:

TABLE 5 Treha- Na CR845•HCl lose Caprate EDTA Formu- Suspension (% (% (%(% lation: Matrix w/w) w/w) w/w) w/w) 8. 10% Capric acid/ 23.17 76.830.00 0.00 Miglyol ® 9. Miglyol ® 18.81 62.37 14.11 4.70 10. Miglyol ®17.92 59.91 12.74 9.43 11. Miglyol ® 17.92 59.91 22.17 0.00 12. 10%Capric acid/ 20.99 69.68 0.00 9.33 Miglyol ®FIGS. 10-14 show bioactivity profiles for formulations 8-12. Table 6shows the bioactivity determined as described above for each of theseformulations:

TABLE 6 Formu- Suspension lation: Matrix % f Std. Dev. SEM 8. 10% Capricacid/ 16.3 14.92 5.27 Miglyol ® 9. Miglyol ® 11.5 6.07 2.15 10.Miglyol ® 12.4 8.95 3.17 11. Miglyol ® 18.4 11.64 4.11 12. 10% Capricacid/ 14.5 10.89 3.85 Miglyol ®

The specifications of each of the U.S. patents and published patentapplications, and the texts of the literature references cited in thisspecification are herein incorporated by reference in their entireties.In the event that any definition or description contained found in oneor more of these references is in conflict with the correspondingdefinition or description herein, then the definition or descriptiondisclosed herein is intended.

The examples provided herein are for illustration purposes only and arenot intended to limit the scope of the invention, the full breadth ofwhich will be readily recognized by those of skill in the art.

What is claimed is:
 1. A formulation from about 18% (w/w) to about 23%(w/w) CR845.HCl (D-Phe-D-Phe-D-Leu-D-Lys[ω(4-aminopyperidine-4carboxylicacid)].HCl), from about 60% (w/w) to about 77% (w/w) trehalose and aglyceride of one or more medium chain fatty acids selected from thegroup consisting of caproic acid, caprylic acid and capric acid; whereinthe CR845.HCl exhibits a bioavailability of greater than 10%.
 2. Theformulation according to claim 1, wherein the glyceride of the one ormore medium chain fatty acids is a mono/di/triglyceride of caprylic acidand/or capric acid.
 3. The formulation according to claim 2, wherein theglyceride of the one or more medium chain fatty acids is adi/triglyceride of caprylic acid and/or capric acid.
 4. The formulationaccording to claim 2, further comprising capric acid or a salt of capricacid.
 5. The formulation according to claim 4, wherein the salt ofcapric acid is sodium caprate.
 6. The formulation according to claim 1,wherein the CR845.HCl(D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopyperidine-4carboxylic acid)].HCl) isspray-dried or crystalized.
 7. The formulation according to claim 2,further comprising a chelating agent.
 8. The formulation according toclaim 7, wherein the chelating agent is EDTA.
 9. The formulationaccording to claim 1, wherein the caprylic/capric fatty aciddi/triglyceride is from about 25% to about 92% (w/w) of the formulation.10. The formulation according to claim 9, further comprising from about5% to about 50% (w/w) of capric acid.
 11. The formulation according toclaim 9, comprising from about 5% to about 20% (w/w) of capric acidand/or from about 5% to about 20% (w/w) of a salt of capric acid. 12.The formulation according to claim 11, wherein the salt of capric acidis sodium caprate.
 13. The formulation according to claim 12, whereinthe CR845.HCl (D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopyperidine-4carboxylicacid)].HCl) exhibits a stability of greater than about 96% stored for 3months at 40° C., 75% relative humidity.
 14. A pharmaceuticalcomposition, comprising the formulation according to claim 1 and apharmaceutically acceptable excipient, diluent or binder.
 15. Thepharmaceutical composition according to claim 14 in an entericallycoated capsule or a capsule having intrinsically enteric properties. 16.A formulation for oral delivery of a kappa opioid receptor agonist,comprising CR845.HCl(D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopyperidine-4carboxylic acid)].HCl)and a glyceride of one or more medium chain fatty acids selected fromthe group consisting of caproic, caprylic and capric acids, wherein theCR845.HCl (D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopyperidine-4carboxylicacid)].HCl) is embedded in trehalose and exhibits a stability of greaterthan about 96% stored for at least a year at 25° C.
 17. The formulationaccording to claim 16, wherein the glyceride of the one or more mediumchain fatty acid is a mono/di/triglyceride of caprylic acid and/orcapric acid.
 18. The formulation according to claim 17, wherein theglyceride of the one or more medium chain fatty acid is adi/triglyceride of caprylic acid and/or capric acid.
 19. The formulationaccording to claim 17, further comprising capric acid or a salt ofcapric acid.
 20. The formulation according to claim 19, wherein the saltof capric acid is sodium caprate.